The 1860 Firth, Pond & Co. edition (linked to above) is "The earliest known copy" (Saunders and Root, The Music of Stephen C. Foster, vol. 2, Smithsonian, 1990, p. 427). Morrison changed the spelling perhaps because he must have known Burke himself. See the following, with additional info on the ship:

"The song is retrospective in other ways, too. The steamboat Glendy Burke (never a sure speller, Foster dropped the "e") had been built in Jefferson, Indiana, in 1851, and named for a New Orleans banker, merchant, and legislator, Glenn D. Burke, with whom Morrison Foster had done business back in 1843. Times had changed since "Oh! Susanna," however, and railroads had overtaken steamboats as the swiftest means of transport. Unlike the Telegraph No. 1 and No. 2, which had been going strong when Foster immortalized them, the Glendy Burke was no longer even afloat. In 1855, the 425-ton side-wheel packer hit a snag and broke up near Cairo. Its wreckage damaged other vessels for decades. Foster's "mighty fast boat" was nothing but a navagational hazard." (Ken Emmerson, Doo-Dah!: Stephen Foster and the Rise of American Popular Culture, Da Capo, 1998, p. 255)

Other info is in William W. Austin, "Susanna," "Jeanie," and "The Old Folks at Home": The Songs of Stephen C. Foster from His Times to Ours, 2nd. ed. (University of Illinois Press, 1987, pp. 240-42).

~Masato